Permanent or nonretrievable type packers are frequently used in well conduits in oil and/or gas wells. While such permanent or nonretrievable packers are normally not removed from the well conduit, there are some occasions which require that such packers be removed. In such event, a milling tool is lowered through the well conduit and the packer is milled up until at least the slips holding the packer from moving upwardly in the well conduit are destroyed. After this, the packer may be moved upwardly and out of the well conduit. However, such a procedure requires milling down all of the packer above the upper slips which becomes an expensive and time-consuming operation. Furthermore, this milling operation becomes much more difficult when used on packers made of so-called premium material such as materials with high chromium and/or nickel content including stainless steels, duplex, monels, and inconels.
The present invention is directed to a normally permanent well packer and method for simplifying the release and milling operation required to mill and retrieve such a packer.